The foods that are rich in nitrogen are proteins. Nitrogen is present in amino acids that serve as basic building blocks of protein synthesis.

Nitrogen rich foods are known as proteins. Meat, poultry, milk, egg and cheese are good sources of high-quality proteins. Legumes such as pinto beans, navy beans and chick peas are sources of low-quality proteins. Animal proteins are considered as high quality proteins as they provide sufficient amount of essential amino acids. Plant proteins are considered as low quality proteins because they lack one or more essential amino acids.

Lamb is the highest protein provider per 100 grams at 29.7 grams of protein. Shell fish such as shrimps, prawns, crabs, and lobsters are also rich sources of proteins. Shell fish provides about 22 to 23 grams of protein per 100 grams. Vegetables such as asparagus, Brussels sprouts and broccoli are good sources of protein. These vegetables contain 3 grams of protein per 100 grams. These sources of proteins can be considered as nitrogen rich foods.

Proteins are the only component of food that contain nitrogen; fat, carbohydrate and dietary fiber do not contain nitrogen. The average nitrogen content of proteins is about 16 percent.